2007 OPEN FORUM AbstractsCOMPARISON OF HAND VENTILATORS IN DELIVERING NITRIC OXIDE.
COMPARISON OF HAND VENTILATORS IN DELIVERING NITRIC OXIDE.
S. M. Baldwin1, A. Alipoon1, J. Pfeifle1, M. Lum1
Background: Delivery of inhaled nitric oxide (iNO) in the event of mechanical ventilatory failure, patient transport or resuscitation is available through the INO Therapeuticsâ INOvent. The manufacturer states with the flowmeter set at 15 LPM, the INOventâs nitric oxide (NO) output is 20 ppm +/-8 when using a NO cylinder concentration of 800 ppm. We tested four commercially available hand ventilators: An Anesthesia Associates Inc. 500mL non-self-inflating (NSI) anesthesia bag, a self-inflating (SI) 3100 series Ventlab Corp. hand ventilator, a 300mL SI Baby Blue II, Vital Signs Corp., and a 240mL SI hand ventilator from Laerdal Medical. We asked several questions:
1. Which hand ventilator would deliver the highest NO concentration?
2. Is 15 LPM, as stated by the manufacturer, the minimum flow rate necessary to overcome the INOventâs shutoff valve and to begin NO delivery?
3. Considering that the 500 mL anesthesia bag is the standard in our NICU, will 8-10 LPM deliver 20 ppm of NO and achieve the desired ventilatory pressures?
4. Can we predict the NO concentration at specific flow rates?
Method: The INOvent was calibrated per manufacturerâs specifications. Each hand ventilator was connected to a DrÃ¤ger Neonatal Test Lung. A pressure manometer and NO sample port was placed proximal to the test lung. The hand ventilators were tested using the following parameters: rate of 30 per minute, peak pressure of 25 cmH2O and a PEEP of 5 cmH2O. We recorded the NO concentration from the sample port at one, two and three minute intervals during flow rates of 1-8, 10, 15 LPM and Flush.
Results: At flow rates less than 3 LPM, none of the hand ventilators delivered any measurable amount of nitric oxide. At 3.5 LPM, all of the hand ventilators delivered less than 1 ppm NO. All bags reached their respective equilibrium states within two minutes when flow rates greater than 3 LPM were used. The non-self-inflating hand ventilator could not meet the rate and pressure study parameters when flows of 1 and 2 LPM were used. FiO2 delivered by all hand ventilators ranged from 95% to 100% at all flow rates tested. See table: below for NO data generated at various flow rates.
Conclusion: The self-inflating hand ventilators performed comparably for NO delivery. Concentrations of NO are flow dependent in all hand ventilator tested. A flow of 15 LPM does not guarantee a concentration of 20 ppm NO will be delivered.
NO at Three Minutes ppm